The murine eye is composed of tissues that are derived from ectoderm, neuroepithelium, neural crest and mesoderm, which contain different cell lineages. It has been thought that multiple signals are involved in the inductive interactions between these different tissues. Although embryologists have tried to identify the signals that are required for lens induction for many years, these molecules remain poorly defined, and no in vitro assay for the lens induction has been established to date. This proposal aims to establish a stable cell line of embryonic lens progenitor cells, and identify some of the important signals and their downstream target genes required for lens induction. The specific aims of this grant application are: 1) To establish progenitor cell lines from ocular lens pit and from non-lens tissue in the eye field; 2) To assess the gene expression profile in lens progenitor cells before and after initiation of progenitor cell differentiation; 3) To assess external signals as candidates for lens induction. The proposed studies should provide novel strategies for isolation and identification of embryonic lens progenitor cells. These cells should be used for many studies, such as identification of the signals and the molecular pathways involved in lens induction and [unreadable] development, inhibition of cell migration, lens regeneration and cell type conversion. [unreadable] [unreadable] [unreadable]